Device for filing commutators for dynamos or motors.



No. 723,399. PATENTED MAR. 24;, 1903.

J. B. MAQINTOSH. DEVICE FOR FILING COMMUTATORS FOR DYNAMOS 0R MOTORS.

APPLICATION FILED JULY 10, 1902.

H0 MODEL.

$0 In x UNIT STATE PATENT OFFICE.

JOSEPH B. MAOINTOSH, OF LEXINGTON, MASSACHUSETTS.

DEVICE FOR FILING COMMUTAIORS FOR DYNAMOS' OR MOTORS.

SPECIFICATION formingpart of Letters Patent N 0. 723,399, dated March 24, 1903. Application filed July 10', 1902'. Serial No. 115,017- (N0 model.)

To all whom it may concern: I

Be it known that I, JOSEPH B. MAOINTOSH, a citizen of the United States, residing at Lex-j ington, county of Middlesex, State of Massachusetts, (whose post-office address is Lexington, Massachusetts,) have invented an Improvement in Devices for Filing Commutators for Dynamos or Motors, of which the following description, in connection with the accompanying drawings, is a specification, like figures on the drawings representing like parts.

After a dynamo or motor has been in use for some time the commutator becomes worn to such an extent as to cause the dynamo or motor to spark. When this occurs, it is necessary to resurface or true up the commutator, and this has heretofore been accomplished by removing the armature-shaft from the motor and placing the same in a lathe, Where the commutator is resurfaced or trued up by a suitable tool or file. This operation necessarily consumes a considerable length of time and requires a good deal of labor.

It is the object of my present invention to provide a novel device by means of which the commutator of the motor and dynamo may be quickly and easily filed or resurfaced whenever such operation is necessary and without necessitating the removal of the armatureshaft from its hearings or the disconnecting of the main wires from the brush-holder or in any way disturbing the electrical connections of the motor or dynamo.

In accordance with my invention I provide a suitable file having a rasping or filing surface shaped to fit the commutator and employ a suitable file-holder for yieldingly sustaining said file, which file-holder is adapted to be removably supported by the brush: holders.

Figure 1 is a view showing in elevation enough of the motor or dynamo to illustrate the operation of my improvement. Fig. 2 is a perspective view of the form of file-holder which I preferably employ. Fig. 3 is an en; larged detail view of one ordinary form of brush-holder now in common use.

In the'drawings, 3 designates a suitable casing in which a motor or dynamo of any suitable construction is inclosed, the form of motor herein shown being a four-pole motor.

the fingers 9 are mounted on an arm 10, which.

is pivotally mounted on a pin 11. A spring 12 operates to yieldingly hold the arm 10 in the position shown in Fig. 3.

, The parts thus far described are commonly used in many classes of dynamos and motors,

and further description thereof is not deemed necessary.

My invention consists in employing asuitable file-holder, which is supported by the brush-holders in such a way that the fileholder may be put in place or removed without disturbing the electrical connections of the dynamo or motor. The particular form or shape of the file-holder will depend upon the construction of the motorto which it is to be applied, and Where the motor is of the 'form herein illustrated the file-holder will preferably comprise a suitable block 15, of woodor anyother suitable material, having the fingers l6 projecting from the ends thereof in the proper position and direction to be received beneath thefingers 9, as'best seen in Fig. l. The said file-holder has an aperture therein through which projects the shank 17 of the file 18, the said file having a rasping or filing surface shaped to fit the commutator 5. I will preferably yieldingly sustain the-file in its holder and will provide means tending normally to hold the file against the commutator. One simple Way of accomplishing this is illustrated in the'drawings, wherein the end of the stem 17 is engaged by the head 20 of the spring-pressed plunger 19. The plunger is shown as being mounted in a suitable yoke 21, and the spring 22, encircling the stem thereof, operates to yieldingly hold the file against the commutator, as will be obvious. It will be understood that the rasping-surface of the file is of sufficient size to cover the entire width of the I do commutator. I will preferably make the stem 17 polygonal in cross-section, so as to prevent the file from turning.

Whenever it is desired to resurface a commutator by means of my device, it is simply necessary to first raise the arms 10 and remove the brushes 6. Thereafter the fileholder 15 may be placed in position, as seen in Fig. 1, the said file-holder being held and retained in such position by the ears or lugs 16, which are clamped beneath the fingers 9. It now the commutator be rapidly rotated, the surface thereof will be properly filed by the engagement of the file 18 therewith, as will be obvious.

To those skilled in the art it will be apparout that the removal or the insertion of the brushes 7 does not disturb in any way the wiring of the dynamo or motor or the electrical connections. With my construction, therefore, it is possible to remove the brushes 7 and put the file-holder in operative position without disturbing in the least any of the wiring. This I consider as quite important, because it makes my invention especially useful in truing up or filing the commutators of motors used in propelling electric cars, for when the car has two motors one of the motors may be cut out of the circuit, its brushes removed, and the file-holder put in place, as illustrated in Fig. 1, after which the car may be driven by means of the other motor, the forward movement of the car of course operatingtorotatethearmaturebeingfiled. Since it is but the work of a moment to remove the brushes and put my improved file-holder in place, it will be obvious that the com mutators of street-car motors may be resurfaced in a minimum length of time without removing the motor from the car or in any way disabling the car. According to the present method it is necessary to either remove the motors entirely from the car or to run the car into a car-barn whenever it is desired to true up thecommutato'rs.

Although I have illustrated and described one particular form of file-holder, yet since I believe that I am the first to devise a fileholder of any description by means of which a suitable file can be yieldingly sustained in proper position to operate upon the commutator of a motor without taking the armature shaft from the motor and without disturbing any of the wiring of the motor I desire to claim the same broadly.

It will be obvious, therefore, that many changes in the details of the construction may be made Without in any way departing from the spirit of my invention as expressed in the appended claims.

Having described my invention, what I claim, and desire to secure by Letters Patent,

- 1. A device for filing commutators while still in place in a motor or dynamo, comprising a file-holder having means adapted to be engaged by the yielding brush-holding fingers of said dynamo or motor, and a file yieldingly carried by said file-holder.

2. A device of the class described comprising a file-holder having ears adapted to be engaged by the fingers of the brush-holder, and a file yieldingly carried by said file-holder and having a rasping-face curved to fit the commutator.

3. A device of the class described comprising a sector-shaped block adapted to set be tween the brush-holders of a four-pole motor or dynamo, and having fingers to be received under the brush-holding fingers, and a file carried by said block and adapted to engage the commutator.

4. A device of the class described comprising a file-holder having lips or projections to be engaged by brush-holders, a file having a stem extending through an aperture in the file-holder and a spring-pressed plunger engaging the end of the stem and operating to yieldingly hold the file against thecommutator.

5. A device of the class described, comprising a file, and a holder therefor, said holder having means adapted to be engaged by the brush-holding fingers.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOSEPH B. MACINTOSH.

Witnesses:

Geo. H. JACKSON, ARTHUR A. MI'roHIE. 

